Researchers have found that high-dose radiation therapy can improve survival for oligometastatic patients, according to findings to be presented at the 2018 Annual Meeting of the American Society for Radiation Oncology (ASTRO). The meeting is scheduled for Oct. 21-24 at the Henry B. Gonzalez Convention Center in San Antonio.
“Traditionally, when a patient had a cancer that spread to other parts of their body—such as to their bones or brain—they were considered to be incurable,” David Palma, MD, PhD, lead author of the research, said in a prepared statement. “But there’s a theory—called the oligometastatic theory—that if a patient only has a few spots of cancer returning, those spots could be killed with radiation or surgery to improve their survival. Now, we’ve been able to show, for the first time in a randomized trial, that high-dose radiation can effectively treat these limited recurrences, and we’ve been able to increase survival by a median of 13 months.”
In what researchers are calling the first randomized, phase II clinical trial of its kind, Palma et al. enrolled a total of 99 patients from Canada, Scotland, the Netherlands and Australia. Each patient had already been treated for cancer, but the cancer returned. The cancers included breast cancer, lung cancer, colorectal cancer and prostate cancer. All patients had a life expectancy of more than six months.
From February 2012 to August 2016, patients were randomized into two treatment groups—palliative standard of care (SOC) treatments and SOC treatments plus stereotactic body radiation therapy (SBRT)—by a 1:2 ratio. Patients who received SBRT lived “considerably longer” than those who did not, according to the statement. Median overall survival was 41 months for patients given SBRT and 28 months for patients who received palliative SOC treatments. SBRT also doubled how long patients lived without cancer growth.
“We were surprised and quite pleased,” Palma said in the statement. “We didn’t expect the survival benefit to be quite so long for patients with metastatic disease.”
“Very serious side effects,” even death, are associated with SBRT. However, Palma explained, “for patients whose cancers have spread, and who are not expected to survive otherwise,” the benefit outweighs the risks.